Deprecated
ICU 2.2
ComposedCharIter is an iterator class that returns all of the precomposed characters defined in the Unicode standard, along with their decomposed forms. This is often useful when building data tables (e.g. collation tables) which need to treat composed and decomposed characters equivalently.
For example, imagine that you have built a collation table with ordering
rules for the canonically decomposed forms of all
characters used in a particular language. When you process input text using
this table, the text must first be decomposed so that it matches the form
used in the table. This can impose a performance penalty that may be
unacceptable in some situations.
You can avoid this problem by ensuring that the collation table contains rules for both the decomposed and composed versions of each character. To do so, use a ComposedCharIter to iterate through all of the composed characters in Unicode. If the decomposition for that character consists solely of characters that are listed in your ruleset, you can add a new rule for the composed character that makes it equivalent to its decomposition sequence.
Note that ComposedCharIter iterates over a static table
of the composed characters in Unicode. If you want to iterate over the
composed characters in a particular string, use Normalizer instead.
When constructing a ComposedCharIter there is one optional feature that you can enable or disable:
Normalizer#IGNORE_HANGUL - Do not iterate over the Hangul
characters and their corresponding Jamo decompositions.
This option is off by default (i.e. Hangul processing is enabled)
since the Unicode standard specifies that Hangul to Jamo
is a canonical decomposition.
ComposedCharIter is currently based on version 2.1.8 of the Unicode Standard. It will be updated as later versions of Unicode are released.
| Modifier and Type | Field and Description |
|---|---|
| private int | |
| private String | |
| public static final char | DONE
Constant that indicates the iteration has completed. |
| private final Normalizer2Impl | |
| private int |
| Access | Constructor and Description |
|---|---|
| public | |
| public | ComposedCharIter(boolean
false for canonical decompositions only;
true for both canonical and compatibility
decompositions. compat, int Optional decomposition features. None are supported, so this is ignored. options)
Deprecated
ICU 2.2
Constructs a non-default ComposedCharIter with optional behavior.
|
| Modifier and Type | Method and Description |
|---|---|
| public String | |
| private void | |
| public boolean | |
| public char |
| curChar | back to summary |
|---|---|
| private int curChar | |
| decompBuf | back to summary |
|---|---|
| private String decompBuf | |
| DONE | back to summary |
|---|---|
| public static final char DONE
Deprecated ICU 2.2 Constant that indicates the iteration has completed.
| |
| n2impl | back to summary |
|---|---|
| private final Normalizer2Impl n2impl | |
| nextChar | back to summary |
|---|---|
| private int nextChar | |
| ComposedCharIter | back to summary |
|---|---|
| public ComposedCharIter()
Deprecated ICU 2.2 Construct a new ComposedCharIter. The iterator will return all Unicode characters with canonical decompositions, including Korean Hangul characters.
| |
| ComposedCharIter | back to summary |
|---|---|
| public ComposedCharIter(boolean compat, int options)
Deprecated ICU 2.2 Constructs a non-default ComposedCharIter with optional behavior.
| |
| decomposition | back to summary |
|---|---|
| public String decomposition()
Deprecated ICU 2.2 Returns the Unicode decomposition of the current character.
This method returns the decomposition of the precomposed character most
recently returned by
| |
| findNextChar | back to summary |
|---|---|
| private void findNextChar() | |
| hasNext | back to summary |
|---|---|
| public boolean hasNext()
Deprecated ICU 2.2 Determines whether there any precomposed Unicode characters not yet returned
by
| |
| next | back to summary |
|---|---|
| public char next()
Deprecated ICU 2.2 Returns the next precomposed Unicode character.
Repeated calls to next return all of the precomposed characters defined
by Unicode, in ascending order. After all precomposed characters have
been returned,
| |